Location marker with retroreflectors

ABSTRACT

A location marker that may be used to provide information to a vehicle, such as an unmanned aerial vehicle (UAV). The location marker may include a plurality of retroreflectors that may form a pattern readable by a vehicle or other device. The pattern may be read to extract an identifier of a location, such as an address or an identifier of a person. A global positioning system (GPS) device may transmit a general location of the location marker to the vehicle, while the location marker may provide a unique visual location identifier to a device within visual range of the location marker. In some embodiments, the location marker may also include lights that may be individually sequenced on and off at different times to create a time domain signal sequence that is readable by the vehicle.

BACKGROUND

Currently, a majority of deliveries are conducted manually by deliverypersonnel going door-to-door. However, the unmanned aerial vehicle (UAV)has great potential as an expedient and energy efficient vehicle fordelivering goods to consumers. For example, after processing an orderfor a product, a UAV may transport the product to a delivery location,such as a consumer's home or office. The UAV may fly autonomously attimes and may navigate to an assigned destination. Often, UAVs rely on aglobal positioning system (GPS) for navigation. However, GPS is subjectto some errors and inaccuracy, and may not afford a UAV accuracy neededto discriminate a correct delivery location from an incorrect deliverylocation, especially when delivery locations are very close together,such as within feet of one another.

Landing markers are sometimes used to guide a vehicle to a specificlanding zone. Often, landing markers are permanent fixtures that arepainted on a landing pad. These landing markers take up physical space,are visually unattractive in typical residential areas, and are notalways visible at night or in inclement weather.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Thesame reference numbers in different figures indicate similar oridentical items.

FIG. 1 is a schematic diagram of an illustrative environment thatincludes a location marker with lights configured to visually identify alocation for an unmanned aerial vehicle (UAV).

FIG. 2 is a block diagram of illustrative architecture of the locationmarker with lights shown in FIG. 1.

FIGS. 3A-D are schematic diagrams of time sequenced light operations ofthe location marker with lights.

FIG. 4 is a schematic diagram of an environment that includes anillustrative directional location marker with lights configured tovisually identify a location for a UAV and at least a directionassociated with an approach to the directional location marker.

FIG. 5 is a flow diagram of an illustrative process initiate thelocation marker and provide a light sequence for a UAV.

FIG. 6 is a flow diagram of an illustrative process to provide a timedomain signal sequence that is readable by a UAV to obtain informationassociated with a location of the location marker.

FIG. 7 is a perspective view of an illustrative location marker thatincludes retroreflectors.

FIG. 8 is a top side view of the illustrative location marker thatincludes retroreflectors shown in FIG. 7.

FIG. 9 is a top side view of an illustrative directional locationmarker.

FIG. 10 is a top side view of an illustrative location marker thatreflects light to create a field of view of less than 360 degrees.

FIG. 11 is a top side view of an illustrative location marker thatincludes retroreflectors and a secondary display area.

FIG. 12 is a top side view of an illustrative location marker thatincludes retroreflectors and lights.

FIGS. 13A-13B are top side views of illustrative location markers thatinclude hoods that hide at least a portion of the markers from certainviewing angles.

FIG. 14 is a perspective view of an illustrative three-dimensionallocation marker.

FIG. 15 is a schematic diagram of an environment that includes anillustrative directional location marker with retroreflectors and a UAVto locate the location marker.

DETAILED DESCRIPTION

This disclosure is directed to a location marker that may be used toprovide information to a vehicle, such as an unmanned aerial vehicle(UAV). In some embodiments, the location marker may include a pluralityof lights which may be individually sequenced on and off at differenttimes to create a time domain signal sequence that is readable by thevehicle. The lights may provide information in various different ways.For example, the specific lights that are illuminated at a certain timemay form a light pattern that includes or is associated withinformation. For example, lights may be illuminated to create a lightpattern, such as a quick response (QR) code or other image code, whichcan be deciphered by a computing device associated with the vehicle.Different light patterns may be displayed over time to provide differentinformation to the vehicle.

In some embodiments, the amount of time that a light is on or off (orboth) may provide information as a time domain signal sequence (e.g.,flashing lights) to the vehicle, such as to provide information such asan SOS signal or other information (e.g., a unique identifier of alocation, etc.). By encoding information into flashing or sequencedlights, the signal may be more easily received and read by a computingdevice even when the imagery is blurry or otherwise includes distortionor poor quality due to inclement weather and/or for other reasons. Invarious embodiments, both the time domain signal sequence and the lightpattern that is illuminated may be used to provide information to thevehicle. For example, the time domain signal sequence may provideidentification information to identify a specific location while thelight pattern may provide approach information, indicate obstacles toavoid, and/or provide other information to the vehicle.

In various embodiments, the location marker may monitor an areaproximate to the location marker to detect presence of obstacles such aspeople, animals, and/or other living or non-living objects that maydisrupt a successful delivery of an item by a vehicle. Upon detection ofsuch obstacles, the location marker may initiate a light control toindicate the presence of the obstacle(s) to the vehicle, possibly as an“abort” message to inform the vehicle to stay clear of the location atleast for a certain amount of time.

In accordance with some embodiments, the location marker may include oneor more retroreflectors that may reflect light from a light source to animage sensor onboard the vehicle. The light source may be the sun, alight onboard the vehicle, a laser onboard the vehicle, and/or anotherlight source. The retroreflectors may be used with different shapes,configured in different patterns, and/or be used with other displays orlights to provide information to the vehicle. Unlike the lightsdescribed above, the retroreflectors typically cannot “turn on” and“turn off”, and thus cannot provide a time domain signal sequence.However, the retroreflectors may be placed in certain locations toenable conveying information to a vehicle, such as a UAV. Theretroreflectors may also provide directionality information based onvarious configurations described below.

The vehicle may be autonomous or semi-autonomous and may be an aerialvehicle, a land-based vehicle, and/or a maritime vessel. The techniques,apparatuses, and systems described herein may be implemented in a numberof ways. Example implementations are provided below with reference tothe following figures.

FIG. 1 is a schematic diagram of an illustrative environment 100 thatincludes a location marker with lights configured to visually identify alocation for an unmanned aerial vehicle (UAV). The environment 100includes a fulfillment center (FC) 102 where a UAV 104 may originate aflight directed to a destination 106, such as a location associated witha recipient of a package 108 transported by the UAV 104.

The UAV 104 may be equipped with one or more image sensors 110 used todetect visible light or non-visible light (e.g., infrared light, etc.).The image sensor(s) 110 may include cameras, such as a stereo camerapair used for guidance purposes by the UAV 104. The image sensor(s) 110may capture imagery of a location that includes a location marker, andmay enable detection of the location marker and possible extraction ofinformation from the location marker, as discussed below.

The UAV may be equipped with a number of components to enable the UAV104 to perform operations during the delivery of the package and toidentify and extract information from a location marker. The componentsmay include at least a flight controller 114 and a marker module 116.The UAV 104 may travel under control of the flight controller 114 andalong a flight path 121 toward the destination 106. The flightcontroller 114 may continually or from time to time provide controls tocause change in a velocity of the UAV, a change in heading, a change inaltitude, a change in orientation, and/or other changes (e.g., pitch,roll, yaw, hover, etc.). In addition, the UAV 104 may execute differentcontrols based on different flight scenarios, such as a takeoff stage, atransport stage, a package deposit stage, and/or a landing stage offlight.

The marker module 116 may detect a location marker 118 via analysis ofimagery that includes the location marker 118 and/or may interpretinformation from the location marker 118. The location marker 118 may beassociated with a specific location 120, such as a physical location todeposit the package 108. However, the location may be associated withother information, such as a waypoint for navigation, an obstacle 125, alocation for an autonomous vehicle (or taxi) to pick up passengers, andso forth. The location marker 118 may include lights that turn on andoff individually to provide information as a time domain signal sequenceand/or may provide a light pattern readable by the marker module 116.The marker module 116, via analysis of the imagery of the locationmarker 118, may determine an identifier associated with the locationmarker 118, which may be associated with a recipient 122 of the package108. In some embodiments, the identifier may be a location identifier.The location identifier may be a unique code, a physical address (e.g.,a street address, a house number, etc.), a customer identifier, and/orother location information (e.g., coordinates, etc.). The identifier maybe input to the location marker by a wireless message, by input controlson the device, by being hardcoded on the location marker, and/or viaother known techniques, such as by plugging in a device to a port on thelocation marker.

For example, the recipient 122 may be assigned an identifier, which isemitted via lights by the location marker 118, to inform the UAV 104 ofa specific location associated with the recipient 122. The location maybe the location of a home or other dwelling, or the location may beassociated with a place of presence of the recipient 122 at a given timeor period of time. For example, a person may bring the location marker118 to a park or other public space, such as where the person is havinga picnic during the afternoon. The location marker 118 may enable a UAVor other vehicle to locate the person. Thus, the location marker 118 maybe portable and may be associated with different locations, as discussedin greater detail below. The identifier emitted by the location marker118 may be different from identifiers emitted by other location markers124, but may not be unique among all location markers.

In some embodiments, the information provided by the location marker 118to the marker module 116, via a light pattern and/or a time domainsignal sequence, may provide the identifier and/or other messages suchas indication of a preferred approach and/or departure to a location,presence of obstacles 125, information about the recipient 122, and/orother information. For example, the light pattern may identify specificinformation to assist the UAV 104 in successfully depositing the package108, including how to deposit the package (e.g., landing, dropping fromthe air, etc.), and/or other instructions, messages, or information.

The location marker 118 may be equipped with a number of components toenable the location marker to perform operations to assist with thedelivery of the package 108. The components may include at least a lightcontroller 126 and a communication module 128, as well as othercomponents discussed below with reference to FIG. 2.

The light controller 126 may cause lights of the location marker 118 toturn on and off to create a time domain signal sequence and/or a lightpattern as described above. The light controller 126 may determine theinformation to provide to the UAV 104, and may convert that informationinto the time domain signal sequence and/or the light pattern. In someembodiments, the light controller 126 may sense a wake signal or otheroccurrence, which may cause the light controller 126 to activate thelights (e.g., change from a low power state to a full operation state,etc.). For example, the light controller 126 may “hear” the UAV 104,and/or capture other signals from the UAV 104, which may be used to wakethe location marker 118. The low power state may be used to conservepower when the location marker 118 is not expected to be used by the UAV104. The light controller 126 may provide initiation sequences or othersequences of lights to provide information such as an indication of anidentifier, a message, a warning, an abort signal, and so forth. Forexample, the light controller 126 may insert predetermined sequences ofthe time domain signal sequence and/or the light patterns prior todifferent types of information to signal to the UAV 104 whichinformation will be provided next via the light controller 126. Thelight controller 126 may obtain information and/or communicate with thecommunication module 128, which is described next.

The communication module 128 may be configured to exchange informationwith other devices, such as a device of a person (e.g., mobile phone,computer, etc.), a command center associated with the UAV 104, a thirdparty device, and/or other devices. For example, the communicationmodule 128 may obtain the identifier to be used by the light controller126, may obtain a message to be emitted by the light controller 126, andso forth. In some embodiments, the recipient 122 (or possibly a centralcommand associated with the fulfillment center 102) may program orotherwise cause specific operation of the location marker 118 viainteraction with the communication module 128, such as through anapplication operating on a device. For example, the recipient 122 maydisable the location marker 118, such as after use of the locationmarker or as a result of theft of the location marker via thecommunication module 128. The recipient 122 may turn the location markeron/off via the communication module 128.

FIG. 2 is a block diagram of illustrative architecture 200 of thelocation marker with lights shown in FIG. 1. The location marker 118 mayinclude a housing 202, which may be relatively flat or may have anothershape, such as a cylinder, pyramid, cube, or other symmetrical ornon-symmetrical volume. The location marker 118 may include one or moreprocessor(s) 204 operably connected to computer-readable media 206. Insome examples, the processor(s) 204 may be operably coupled to thecomputer-readable media 206 via one or more of a system bus, a data bus,an address bus, a PCI bus, a Mini-PCI bus, and any variety of local,peripheral and/or independent busses. Executable instructions stored onthe computer-readable media 206 can include an operating system, thelight controller 126, the communication module 128, a detection module208, and other modules and programs that are loadable and executable bythe one or more processor(s) 204. Examples of such programs or modulesinclude, but are not limited to sensor algorithms, approach pathanalysis algorithms, network connection software, and control modules.In some examples, computer-readable media 206 can also include a datastore 210 to store customer data (e.g., customer identification,customer preference data, etc.), location data and the like.

Various instructions, methods, and techniques described herein may beconsidered in the general context of computer-executable instructions,such as program modules, executed by one or more computers or otherdevices. Generally, program modules include routines, programs, objects,components, data structures, etc. for performing particular tasks orimplementing particular abstract data types. These program modules canbe implemented as software modules that execute on the processing unit,as hardware, and/or as firmware. Typically, the functionality of theprogram modules may be combined or distributed as desired in variousembodiments. Embodiments may be provided as a computer program productincluding a non-transitory machine-readable storage medium having storedthereon instructions (in compressed or uncompressed form) that may beused to program a computer (or other electronic device) to performprocesses or methods described herein. Further, embodiments may also beprovided as a computer program product including a transitorymachine-readable signal (in compressed or uncompressed form). Examplesof machine-readable signals, whether modulated using a carrier or not,include, but are not limited to, signals that a computer system ormachine hosting or running a computer program can be configured toaccess, including signals downloaded through the Internet or othernetworks. For example, distribution of software may be by an Internetdownload.

The location marker 118 may include light(s) 212, which may be a singlelight, an array of lights, a grid of lights, and/or other configurationof lights that may be individually turned on and off to create a lightpattern and/or to provide a time domain signal sequence. The light(s)212 may be controlled by the light controller 126 to provide informationto the UAV 104, such as approach information, location information,obstacle information, and/or other information. The lights 212 may emitvisible light, non-visible light (e.g., infrared light, etc.), or acombination of both.

In some embodiments, the location marker 118 may include a GPS receiver214 (“GPS”) to identify a location of the location marker 118. The GPS214 may provide coordinates of the location marker to another device,such as via the communication module 128. However, the information fromthe GPS 214 may include some possible error due to weather and/or otherfactors. Due to this error and because other location makers may belocated near the location marker 118, the location marker 118 mayprovide visual information to the UAV 104 via the light(s) 212 asdiscussed herein. The GPS 214 may provide the coordinates to the UAV 104via a user device and/or via the communication module 128 usingcommunication device 224, either directly to the UAV 104 or via acommand center associated with the fulfillment center 102.

The communication device 224 may facilitate communications, undercontrol of the communication module 128, to the UAV 104, to a centralcommand, and/or to a device associated with the recipient 122. Thecommunication device 224 may provide information and/or data viaBluetooth®, Wi-Fi, a mobile telephone network interface, and/or otherwired or wireless hardware configured for exchange of data signals. Thecommunication device 224 may be a wireless radio.

In various embodiments, the location marker 118 may include sensors 216,such as one or more of a motion detector 218, a camera 220, and/or amicrophone 222. The microphone 222 may be a microphone array, which mayenable determining a direction of a sound, among other possible uses ofmicrophone arrays. The sensors 216 may be used by the location marker118 to detect presence of the UAV 104, presence of obstacles, and/orpresence of moving objects, such as people, other vehicles, and animals,and so forth. The sensors 216 may provide input to the light controller126, which may cause the lights 212 to turn on or off individually toprovide information to the UAV 104 and/or to the recipient 122. Forexample, the light controller 126 may cause lights to flash apredetermined way or in a predetermined pattern to communicate a warningto the UAV and/or the recipient. In some embodiments, the warningmessages may be communicated in different ways. The microphone 222 maybe used to “hear” the UAV 104 to determine presence of the UAV 104. Themicrophone 222 may also be used to detect presence of people and/orother living beings (e.g., a barking dog, a bird, etc.).

In various examples, the communication module 128 may receive, via thecommunication device 224, an initiation signal from the UAV 104delivering a package, and may provide delivery guidance to the UAV 104by activating light 212. The light controller 126 may include logic tocause the lights to turn on and off to indicate a delivery location. Invarious embodiments, the light controller 126 may encode the signalindicating the delivery location to prevent fraud, theft, or spoofing.In such embodiments, the signal may be encoded by pulsing a customerspecific code, varying the wavelength of the signal, varying thefrequency of the signal, and/or varying the rates of the foregoing.

In some embodiments, the delivery location may be a pre-determinedlocation in proximity to the location marker 118. In other examples, thedelivery location may be determined real-time based on the size of theUAV, the size of the package, obstructions present in a pre-determineddelivery location and/or other factors.

In various embodiments, the light controller 126 may include logic toreceive input from the sensors 216 indicating an obstruction at orproximate to the delivery location. In some embodiments, responsive tothe input, the light controller 126 may transmit, via the lights 212, awarning signal to the UAV that it is not clear to deliver the package108. In some examples, the warning signal may include light-basedinstructions on where to hold, hover, or land until the delivery area isclear. In other examples, the UAV 104 may have a pre-programmed locationto hold, hover, or land in the event that an obstruction is present atthe delivery area.

In some embodiments, the detection module 208 may include logic toprogram the one or more sensors 216 to monitor the delivery area toensure the obstruction is no longer at or proximate to the deliverylocation. The one or more sensors 216 may observe the delivery locationcontinuously for a pre-determined time interval, or momentarily afterthe predetermined time interval has passed, to ensure the obstruction isno longer present. For example, the motion detector 218 may observe thedelivery location for 1 minute, and responsive to a lack of motiondetected during the 1 minute time interval, the light controller 126 maytransmit a message to the UAV 104 via activation of certain lights ofthe lights 212 that the delivery location is clear to deliver thepackage 108.

In some examples, responsive to an input that motion is detected in thearea continuously or intermittently during the time interval, and/or isdetected after the time interval has passed, the light controller 126may transmit a message to the UAV 104 via light patterns and/or flashingof lights to indicate that the delivery location is obstructed. Themessage may include an instruction to return to a base location, to flyto a re-charging station, or to continue to hold until a second timeinterval has passed. In some examples, the location marker 118 may beprogrammed to execute multiple iterations of time intervals until theobstruction is clear and/or the location marker 118 determines that theUAV is departing or has departed.

In various embodiments, the detection module 208 may include logic toprogram the one or more sensors 216 to detect an obstacle in an approachpath of the UAV 104 (e.g., flight path from an initial position of theUAV 104 to the delivery area). In other embodiments, the detectionmodule 208 may include one or more pre-programmed obstacles proximate tothe delivery area. In still yet other examples, the detection module 208may access obstacle information in the data store 210. In response to adetermination that one or more obstacles is present in the approach pathand/or proximate to the delivery area, the light controller 126 maycause the lights 212 to transmit a warning of the one or more obstaclesto the UAV 104, possibly including location information associated withobstacles (e.g., which side of the location marker the obstacles arenear, etc.).

As briefly described above, the location marker 118 can include one ormore communication devices 224 for exchanging messages with variouscustomer devices, a UAV, a central delivery system, and/or othernetworked devices. For example, responsive to verifying the successfuldelivery of the package, the communication module 128 may send, via thecommunication device 224, a confirmation message to the customer and/orthe central delivery system. For example, the location marker 118 maysend a delivery confirmation to the recipient 122 via text message.

In various embodiments, the location marker 118 may be powered by one ormore power source 226. In some embodiments, the power source 226 may beone or more batteries. However, the power source 226 may be a powerinverter configured to receive power from a power outlet, a solar panel,a wind generator, or other power source.

In some embodiments, the communication module 128 may transmit, via thecommunication device 224, an indication to the customer and/or thecentral delivery system of the degraded power system and/or low poweravailable from the one or more batteries. For example, the communicationmodule 128 may send the customer a message that batteries are low. Invarious embodiments, the indication of the battery power may accompany amessage of an upcoming scheduled delivery.

FIGS. 3A-D are schematic diagrams of time sequenced light operations ofthe location marker with lights. As discussed above, the lightcontroller 126 may cause the lights 212 to individually turn on and offto create a time domain signal sequence, a light pattern, or both. Forexplanation purposes, the lights 212 are show as a grid of lights.However, other configurations of lights may be used to perform similaroperations. As shown throughout the drawings, black squares representlocations of lights turned on (activated) while white or blank locationsshow lights turned off (not activated).

FIG. 3A shows use of a first light pattern 300. The first light pattern300 includes a first light configuration where some lights are activated(turned on) while others are not activated (turned off) at a first time(t=1). As shown in FIG. 3A, shaded lights are turned on, such as aninterior light 302 within the grid. Bounding lights 304 may be turned onwhen one or more interior lights are turned on to enable a device todetermine a location of the interior light relative to the boundinglights, thus enable reading of a light pattern. The light pattern may bea code, which may be translated into useful information, such as anidentifier of the location marker 118 and/or a message. The lightpattern may be a result of the lights activated at a time, such as t=1.As shown in FIG. 1A, at t=2, 3, 4, 5, and 6, the light pattern remainsactive. Thus, the light pattern is provided in this example, but no timedomain signal sequence is provided.

FIG. 3B shows a first time domain signal sequence 308 formed by changinglights individually over different times. In FIG. 3B, all lights areshown as being activated at t=1, 3, 4, and 6, and all lights are show asbeing non-activated at t=2 and 5. This activation of lights maycommunicate an identifier of the location marker 118 and/or a message orportion thereof assuming more time passes to provide more frames. Eachchange in light may be consider a frame. Thus, FIG. 3B shows six frames.The length of time a frame is shown and or a time between the frames mayprovide information to a device, such as a UAV. Thus, the lights maypulse to provide a message, like S-O-S, among many other possiblemessages.

FIG. 3C shows a first hybrid light signal 310 that includes a timedomain signal sequence and a light pattern. The light pattern is“flashed” to provide information of both the light pattern and alsoother information by the flashing, which provides the time domain signalsequence. The light pattern is provided at t=1, 3, 4, and 6, while thetime domain signal sequence is provided by the occurrence of all theframes from t=1 to t=6. Here, the time domain signal sequence mayprovide an identifier while the light pattern may provide a message, orvice versa, to the UAV 104. In some embodiments, a more critical orimportant message may be provided by the time domain signal sequencesince it may be more perceivable in inclement weather, such as whencaptured imagery is blurred or otherwise not clear or of high quality topossibly read or be analyzed for the light pattern.

FIG. 3D shows a second light pattern 312 followed by an emergency code314 that interrupts the light pattern to provide time-sensitiveinformation to the UAV 104. For example, the emergency code 314 mayinform the UAV 104 of presence of a person near the location marker 118,a change in weather, a request to abort deposit of the package, and/orprovide other information to the UAV 104. The emergency code mayterminate when an associated emergency condition has concluded, whenappropriate. In some embodiments, the light controller 126 may thencause the lights to emit the light pattern 312 or another arrangement oflights as a light pattern and/or the time domain signal sequence asdiscussed above.

FIG. 4 is a schematic diagram of an environment 400 that includes anillustrative directional location marker 402 configured to visuallyidentify the location 120 for the UAV 104 to deposit the package 108 andat least a direction associated with an approach to the directionallocation marker 402.

The directional location marker 402 may include a shape that, whenanalyzed by the UAV 104 or other device, communicates a direction 404.The direction 404 may be determined based on how the recipient 122places or orients the directional location marker 402. The direction 404may cause the UAV to determine an approach to the location 120, such asalong the direction 404. The direction 404 may be selected to cause theUAV 104 to avoid obstacles 125, such as trees, equipment, animals, andpeople.

In some embodiments, the directional location marker 402 may emit lightas the light pattern and/or as the time domain signal sequence toprovide additional information to the UAV 104, such as a glide slope 406associated with an approach angle θ 408. For example, activation ornon-activation of lights may convey the UAV's alignment with the glideslope 406 (e.g., control correction information) or may communicate theangle θ 408 of the glide slope 406. The activation or non-activation ofthe lights may convey other information, such as a side of thedirectional location marker 402 nearest an obstacle, and/or otherobstacle location information. The activation of lights may change,under control of the light controller 126, as the UAV 104 approaches thedirectional location marker 402, such as when conditions change, toprovide different information, to provide an emergency code, and/or forother reasons.

FIGS. 5 and 6 are flow diagram of illustrative processes illustrated asa collection of blocks in a logical flow graph, which represent asequence of operations that can be implemented in hardware, software, ora combination thereof. In the context of software, the blocks representcomputer-executable instructions stored on one or more computer-readablestorage media that, when executed by one or more processors, perform therecited operations. Generally, computer-executable instructions includeroutines, programs, objects, components, data structures, and the likethat perform particular functions or implement particular abstract datatypes. The order in which the operations are described is not intendedto be construed as a limitation, and any number of the described blockscan be combined in any order and/or in parallel to implement theprocesses.

FIG. 5 is a flow diagram of an illustrative process 500 initiate thelocation marker and provide a light sequence for a UAV. The process 500is described with reference to the environment 100 and the architecture200. Of course, the process 500 may be performed in other similar and/ordifferent environments.

At 502, the location marker 118 may search for a wake signal. The wakesignal may be a signal to cause the light controller 126 to emit lightas a light pattern, a time domain signal sequence, or both using anormal power state. The location marker 118 may operate in a low powerstate while searching for the wake signal. The wake signal may be asound of the UAV or a sound from the UAV captured by the microphone 222and processed by the detection module 208. For example, the UAV's rotorblades may emit a unique sound profile or signature that is the wakesignal (when processed by the microphone 222). In some embodiments, thewake signal may be a visual of the UAV or a portion thereof captured bythe camera 220 and/or the motion detector 218, and processed by thedetection module 208. However, the wake signal may be an elapse of time,such that the location marker 118 wakes at a specific time, such as anearliest time the UAV 104 is anticipated to arrive or be in view of thelocation marker 118. In some embodiments, the wake signal may be aspecific signal to wake a specific location marker 118, such that thewake signal includes a unique identifier and/or or other specificinformation. The wake signal may be provided a user, such as via a userdevice or a control on the location marker 118. In some embodiments, thecommunication module 128 may receive the wake signal from the UAV 104,such as via a wireless signal transmitted from the UAV 104.

At 504, the detection module 208 may positively identify the wake signalas one of many possible wake signals discussed above. Upon or afteridentification of the wake signal, the location marker may change apower setting from a low power state to a normal power state and mayinitiate lights. For example, the light controller 126 of the locationmarker 118 may cause the lights 212 to turn on and off individuallydisplay an initiate signal or other signal which may be visible to theUAV 104.

At 506, the detection module 208 may scan an area proximate to thelocation marker 118 to determine if any threats are present that mayprevent the UAV 104 for successfully deposing the package 108 on thelocation 122. For example, the detection module 208 may use the motiondetector 218 to determine presence of people, animals, vehicles, and/orother moving objects (e., leaves on a tree, a flag on a flagpole,clothes on a clothes line, etc.). The detection module 208 may use thecamera 220 or other image sensor to identify other obstacles near thelocation marker 118, such as trees, a swing set, and/or other obstacles.

At 508, the light controller 126, based on information from thedetection module 208 gathered at the operation 506, may determinewhether to emit an abort message or other emergency message via thelights 212. The abort message or other emergency message may be signaledby predetermined light pattern, a predetermined time domain signalsequence, or both. When the light controller 126 determines to emit theabort message or other emergency message (following the “yes” route fromthe decision operation 508), then the process 500 may advance to anoperation 510. At 510, the light controller 126 may cause the lights 212to turn on and off to emit the abort message or other emergency messagevia at least one of the predetermined light pattern or the predeterminedtime domain signal sequence.

Returning to the decision operation 508, when the light controller 126determines not to emit the abort message or other emergency message(following the “no” route from the decision operation 508), then theprocess 500 may advance to an operation 512. At 512, the lightcontroller 126 may cause the lights 212 to turn on and off to signal anidentification of the location marker 118 and/or a message via at leastone of the predetermined light pattern or the predetermined time domainsignal sequence. For example, the light pattern may provide a messagewhile the time domain signal sequence may provide the identification ofthe location marker 118 as being associated with a specific person, suchas the recipient 122. However, the light pattern may provide theidentification while the time domain signal sequence may provide themessage, in some instances.

Following either operation 510 or 512, the process 500 may advance to adecision operation 514 to determine whether to discontinue the lightsand to enter the low power state. For example, the light controller 126may receive a signal from the detection module 208 that the package 108has been deposited, the UAV 104 has departed the area, and/or otherevent information. In some embodiments, the light controller 126 maydetermine to discontinue the lights after a predetermined amount of time(e.g., 3 minutes, 30 minutes, etc.), or in response to user input. Thesignal may be provided by a user, such as via a user device or a controlon the location marker 118 to discontinue the lights. This control mayprevent unauthorized use of the location marker 118.

When the light controller 126 determines not to discontinue the lights(following the “no” route from the decision operation 514), then theprocess 500 may advance to the operation 506 and continue with theprocess 500 as described above. When the light controller 126 determinesto discontinue the lights (following the “yes” route from the decisionoperation 514), then the process 500 may advance to an operation 516. At516, the light controller 126 may discontinue turning the lights on andthe location marker 118 may enter a low power state.

FIG. 6 is a flow diagram of an illustrative process 600 to provide atime domain signal sequence that is readable by a UAV to obtaininformation associated with a location of the location marker. Theprocess 600 is described with reference to the environment 100 and thearchitecture 200. Of course, the process 600 may be performed in othersimilar and/or different environments.

At 602, the light controller 126 may cause the lights 212 to turn on andoff to emit light to provide an initial light sequence of a lightpattern and/or a time domain signal sequence. The initial sequence mayinform the UAV 104 and/or another device that an identifier will beprovided by the light controller 126 following the initial lightsequence.

At 604, the light controller 126 may cause the lights 212 to turn on andoff to emit light to provide an identifier associated with the locationdevice and/or the recipient. The identifier may be provided via a lightpattern and/or a time domain signal sequence. The light controller 126may emit the identifier immediately after the initial sequence or aftera delay.

At 606, the light controller 126 may cause the lights 212 to turn on andoff to emit light to provide a message associated with the locationdevice and/or the recipient. The message may be provided via a lightpattern and/or a time domain signal sequence. The light controller 126may emit the message immediately after the identifier or after a delay.In some embodiments, the message may be provided before the identifier.As described above, the operations 604 and 606 may be performed inparallel when the identifier and the message are provided by the timedomain signal sequence and light pattern, respectively, or vice versa.

At 608, the light controller 126 may determine whether to repeat theidentifier, the message, or both. For example, the light controller 126may receive information from the communication module 128 and/or thedetection module 208 to determine whether to repeat the identifierand/or the message, such as based on whether the UAV is still presentand/or other information. The light controller 126 may determine whetherto repeat the identifier, the message, or both based on a duration oftime of operation of the process 600 and/or a number of iterations ofthe process 600.

When the light controller 126 determines to repeat the identifier, themessage, or both (following the “yes” route from the decision operation608), then the process 600 advances to the operation 602 and the process600 may continue as described above. When the light controller 126determines not to repeat the identifier, the message, or both (followingthe “no” route from the decision operation 608), then the process 600advances to an operation 610. At 610, the light controller 126 maydiscontinue turning the lights on and the location marker 118 may entera low power state.

FIG. 7 is a perspective view of an illustrative location marker 700 thatincludes retroreflectors. The location marker 700 may include a housing702, which may a generally flat shape or a three-dimensional shape suchas a cylinder, a pyramid, a cube, or other three-dimensional shape. Thelocation marker 700 may include at least one surface that includesretroreflectors 704, which reflect at least some light from a givendirection back to that direction. The retroreflectors may be formedusing conventional techniques, such as those used to createretroreflectors on traffic signs. However, the retroreflectors 704 maybe laid out on the housing 702 in a grid, an array, or other pattern orconfiguration which can be read by a device, such as the UAV 104 todetermine an identifier and/or a message. The identifier may be a uniqueidentifier associated with a person, an identifier of a limited set ofidentifiers (e.g., 1-99, A-Z, etc.), and/or an identifier thatidentifies the device as a location marker.

The location marker 700 may include retroreflectors at boundinglocations 706 to provide a bounds for possible locations of theretroreflectors on the location marker 700. For example, the boundinglocations 706 may be corners of a square or a perimeter or part of aperimeter of a circle.

Interior retroreflector locations 708 may form a pattern orconfiguration which can be read by a device, such as the UAV 104 todetermine an identifier and/or a message. For example, theretroreflectors may be arranged to form a QR code or other image code.In some embodiments, the location marker 700 may enable a UAV todistinguish a delivery location from a nearby delivery location, evenwhen the delivery locations in close proximity (within 10 feet or less)based on unique patterns of groupings of the retroreflectors located onthe location marker 700.

In some embodiments, at least one of the plurality of retroreflectorsmay be movable relative to a housing that secure placement of theretroreflectors. For example, the retroreflectors may removable coupleto a grid or other features on a housing to enable a user to reconfigurea pattern formed by the retroreflectors. By reconfiguring the pattern,users can customize the pattern to provide different information, suchas different identifier information, information about obstacles,information to guide an approach of the UAV 104, and/or otherinformation. The user may determine a pattern using a reference, such asa website or printed documentation, which may guide the user's create ofpatterns readable by the UAV 104 and/or by other devices. Theretroreflectors may slide into different locations, couple and decouple,or otherwise be moveable relative to the housing.

FIG. 8 is a top side view of the illustrative location marker 700 thatincludes retroreflectors shown in FIG. 7. As shown in FIG. 8, theretroreflectors may be aligned on a grid, however other arrangements maybe used to lay out the retroreflectors. The pattern formed by theretroreflectors may be symmetrical or may be non-symmetrical, dependingon the algorithm used to generate and/or read the patterns to convertthe location of individual groups of retroreflectors (e.g., smallsquares or other groups of retroreflectors, etc.) into meaningfulinformation, such as an identifier or a message. In some embodiments,the location of the groups of retroreflectors may provide directionalityinformation, which is further explained below. The directionality may beused to indicate an approach route to the location marker and/or adeparture route from the location marker, presence and/or locations ofobstacles, and/or other information.

FIG. 9 is a top side view of an illustrative directional location marker900. The directional location marker 900 may include retroreflectorslocated at bounding locations 902, which when identified by the UAV 104or by another device, may enable the UAV 104 or other device todistinguish a first end 904 from a second end 906. By distinguishing thefirst end 904 from the second end 906, the UAV 104 or other device mayinfer directionality, which may be used to provide information to theUAV 104 or other device. For example, the directionality may be used toindicate an approach route to the location marker and/or a departureroute from the location marker, presence and/or locations of obstacles,and/or other information. Other groups of retroreflectors 908 may bepresent on the directional location marker 900 and may be used toprovide an identifier and/or a message to the UAV 104 and/or otherdevice. Thus, the directional location marker 900 may provideinformation such as a unique identifier, an approach angle, an approachdirection, and/or other information based on the shape of thedirectional location marker bounded by the bounding locations 902 and bylocations of the groups of retroreflectors 908 on the directionallocation marker 900. In various embodiments, the directional locationmarker 900 may enable a UAV to distinguish a delivery location from anearby delivery location, even when the delivery locations in closeproximity (within 10 feet or less) based on unique patterns of groupingsof the retroreflectors located on the directional location marker 900.

FIG. 10 is a top side view of an illustrative location marker 1000 thatreflects light to create a field of view of less than 360 degrees. Thelocation marker 1000 may include retroreflectors 1002 that reflect lightin some directions but not all directions. For example, light from afirst direction 1004, a second direction 1006, or a third direction 1008may be reflected back to the source of the light. However, based on thelayout and/or design of the retroreflectors 1002, light from a fourthdirection 1010 may not be reflected back to the source of the light. Theangle where light is not directed back to the source of light may beselected based on design requirements, and may vary based on locationmarkers. A recipient may request a location marker 1000 with a specificangle where light is not reflected back for various reasons. Forexample, the UAV 104 may not detect the retroreflectors when approachingfrom the fourth direction 1010, which may provide the UAV 104 withinformation about the location of the delivery location, the recipient,the identifier, obstacles, an approach direction, a departure direction,and/or other information. As an example, the location marker 1000 may beplaced by a recipient in such a way that the UAV would not detect thelocation marker from the fourth direction and the fourth direction maybe purposely aligned with a path that intersects or nearly intersects anobstacle that the recipient desires the UAV to avoid, such as a chickencoop or other obstacle. The design of the retroreflector 1002 shown inFIG. 10 is for explanation purposes. The actual design of directionalretroreflectors is understood to be known by those with skill in the artof manufacture and design of retroreflectors. Like the location marker700, the location marker 1000 includes retroreflectors in boundinglocations 1012, as well as groups of retroreflectors 1014 that create areadable identifier and/or message.

FIG. 11 is a top side view of an illustrative location marker 1100 thatincludes a first area 1102 with groups of retroreflectors 1104 and asecondary area 1106 that may be a display area. The second area mayinclude a static display, such as a graphic, or a movable display, suchas a liquid crystal display, an organic LED display, an electronic inkdisplay, and/or any other type of display that may be used to conveyinformation to people and/or other devices via image capture using imagesensors. For example, the display may create a bar code or otherscannable code (e.g., a QR code or other type of fiducial) that can becaptured by the UAV as the UAV passes close to the location marker 1100.The arrangement of the groups of retroreflectors 1104 in the first area1102 may provide an identifier and/or a message readable by the UAV 104or another device. Like the location marker 700, the location marker1100 includes retroreflectors in bounding locations 1108, as well as thegroups of retroreflectors 1104 that create a readable identifier and/ormessage.

FIG. 12 is a top side view of an illustrative location marker 1200 thatincludes a first area 1202 with groups of retroreflectors 1204 and asecond area 1206 that includes lights 1208. The lights 1208 in thesecond area 1206 may be under control of the light controller 126described above, and may operate as discussed above with reference toFIGS. 1-6. Thus, the lights may individually be turned on and off attimes to create a light pattern and/or to provide a time domain signalsequence. The retroreflectors may provide the same information as thelights or the retroreflectors may be used to provide differentinformation. For example, the retroreflectors may provide directionalityinformation while the lights may provide an identifier and/or a messagewhen read by the UAV 104 or another device. However, the arrangement ofthe groups of retroreflectors 1104 in the first area 1202 may provide anidentifier and/or a message readable by the UAV 104 or another device.Like the location marker 700, the location marker 1100 includesretroreflectors in bounding locations 1210, as well as the groups ofretroreflectors 1204 that create a readable identifier and/or message,or other information.

FIGS. 13A-13B are top side views of illustrative location markers thatinclude hoods that hide at least a portion of the markers from certainviewing angles. FIG. 13A shows a perspective view of an illustrativelocation marker 1300 that includes a simple hood 1302 that may blockview of one or more lights (or retroreflectors) included on the locationmarker when viewed from a particular area. Multiple hoods may be used toblock a view form an area, such as a hood for each light, each group ofretroreflectors (e.g., each pixel). However, a single hood may also beused for the whole location marker. As shown, the location marker 1300may be viewable from a first direction 1304, a second direction 1306,and a third direction 1308. However, the presence of the simple hood1302 may block view of the location marker 1300 from a fourth direction1310. By blocking the view for a direction, the location marker 1300 mayprevent a vehicle from approaching form that direction, area, or angle,or may otherwise communicate information to the vehicle regarding thisarea/direction where the lights and/or retroreflectors of the locationmarker 1300 are not fully visible. As an example, the use of the hoodmay cause the UAV 104 to approach from one of the directions other thanthe fourth direction 1310.

FIG. 13B shows a perspective view of an illustrative location marker1300 that includes a full hood 1312 that may block view of one or morelights (or retroreflectors) included on the location marker when viewedfrom a particular area. Multiple hoods may be used to block a view forman area, such as a hood for each light, each group of retroreflectors(e.g., each pixel). However, a single hood may also be used for thewhole location marker. As shown, the location marker 1300 may beviewable from a first direction 1304. However, the presence of the fullhood 1312 may block view of the location marker 1300 from a seconddirection 1316, a third direction 1318, and a fourth direction 1320. Byblocking the view for multiple directions, the location marker 1300 mayprevent a vehicle from approaching form those directions, areas, orangles, or may otherwise communicate information to the vehicleregarding these areas/directions where the lights and/or retroreflectorsof the location marker 1300 are not fully visible. As an example, theuse of the full hood 1312 may cause the UAV 104 to approach from firstdirection 1314, which may cause the UAV 104 to avoid obstacles. An angleθ 1322 of the full hood 1312 may be used to communicate a maximum glideslope to the UAV.

The hoods shown in FIGS. 13A and 13B may be used with any otherembodiment described herein, including embodiments that use lights,retroreflectors, or both. Other hood designs are contemplated whichblock view of at least a portion of the lights and/or retroreflectors ofthe location markers to achieve a design consideration. The hoods mayprovide additional benefits besides blocking the lights from view fromcertain angles. Additional benefits may include protecting the locationmarker from weather (e.g., rain, snow, etc.) and reducing emission ofstray light to appease neighbors, for example.

FIG. 14 is a perspective view of an illustrative three-dimensionallocation marker 1400. The three-dimensional location marker 1400 mayinclude lights and/or retroreflectors at bounding locations 1402, whichmay enable the UAV 104 or another device to determine a boundary of atleast a side of the three-dimensional location marker 1400. Thethree-dimensional location marker 1400 may be formed from virtually anyshape, including cylindrical shapes, pyramids, cubes, and/or otherthree-dimensional shapes which enable a view of lights and/orretroreflectors from a wide range of angles or locations around thethree-dimensional location marker 1400. In some embodiments, thethree-dimensional location marker 1400 may include sides 1404, such as afirst side 1404(1), a second side 1404(2), and so forth. Each side maydisplay a same pattern and/or time domain signal sequence, or some sidesmay display different patterns and/or time domain signal sequence.Interior lights or grouping of retroreflectors 1406 may be used toprovide the same pattern (for lights and/or retroreflectors) and/or timedomain signal sequence (for lights).

FIG. 15 is a schematic diagram of an environment that includes anillustrative directional location marker 1500 with retroreflectors and aUAV to locate the location marker. The environment 1500 is similar asthe environment 100 described with reference to FIG. 1, except FIG. 15shows a location marker 1502 as including retroreflectors. Thus, thelocation marker 1502 may be similar to the location marker 700 or otherlocation markers described above that include or can includeretroreflectors.

To identify the location marker 1502 and read information based on apattern of groupings of retroreflectors 1504, light is directed to thelocation marker 1502. The light may be directed from a light source 1506onboard a vehicle, such as onboard the UAV 104. However, external lightsources may also be used to cause light to be reflected from theretroreflectors and back to the UAV 104 or other device. For example,the retroreflectors may reflect sunlight from the sun 1508, which may becaptured by image sensors 110 of the UAV 104. In some embodiments, themarker module 116 may control the light source 1506 and/or direction ofthe light source to enable the light sensors 110 to capture lightreflected back to the UAV from the retroreflectors of the locationmarker 1502. In various embodiments, the flight controller 114, viainputs from the marker module 116, may approach the location marker 1502at an angle relative to the angle of the sun 1508 with respect to thelocation marker 1502 such that the sunlight is reflected to the UAV 104for capture by the image sensors 110. In the latter scenario that usesthe sunlight, the light source 1506 may not be used.

CONCLUSION

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Rather,the specific features and acts are disclosed as illustrative forms ofimplementing the claims.

What is claimed is:
 1. An apparatus, comprising: a housing to form athree-dimensional shape, the housing including a base; and a pluralityof retroreflectors arranged about the housing, one or more firstretroreflectors of the plurality of retroreflectors arranged along afirst plane to form a first three-dimensional pattern and one or moresecond retroreflectors of the plurality of retroreflectors arrangedalong a second plane to form a second three-dimensional pattern, thefirst three-dimensional pattern readable by a vehicle that is in view ofthe one or more first retroreflectors to communicate at least a locationidentifier to the vehicle.
 2. The apparatus as recited in claim 1,wherein the location identifier includes an address of a deliverylocation.
 3. The apparatus as recited in claim 1, wherein the locationidentifier is one of a group of different location identifiers, thelocation identifier being associated with a person.
 4. The apparatus asrecited in claim 1, wherein the one or more first retroreflectors isarranged as a grid, the first three-dimensional pattern being formed onthe grid based on placement of individual retroreflectors on the grid.5. The apparatus as recited in claim 1, further comprising a pluralityof lights arranged about the first plane, the plurality of lights undercontrol of a light controller, and wherein the light controllerselectively causes the plurality of lights to turn on and off to form atime domain signal sequence.
 6. The apparatus as recited in claim 1,wherein the vehicle is an unmanned aerial vehicle (UAV).
 7. Theapparatus as recited in claim 1, wherein the second three-dimensionalpattern is different from the first three-dimensional pattern.
 8. Theapparatus as recited in claim 1, wherein the second three-dimensionalpattern includes the first three-dimensional pattern.
 9. The apparatusas recited in claim 8, wherein the plurality of retroreflectors furthercomprises one or more third retroreflectors of the plurality ofretroreflectors arranged along a third plane to form a thirdthree-dimensional pattern.
 10. The apparatus as recited in claim 1,wherein the first plane includes at least one hood that physicallyblocks a view of the one or more first retroreflectors from a firstangle of view while allowing view of the one or more firstretroreflectors from a second angle of view.
 11. The apparatus asrecited in claim 1, wherein at least one of the plurality ofretroreflectors is movable relative to the housing.
 12. A locationmarker comprising: a housing including a base and a surface opposite thebase; and a plurality of retroreflectors arranged about the surface toform a pattern, the pattern readable by an unmanned aerial vehicle (UAV)that is in view of the plurality of retroreflectors to communicate alocation identifier to the UAV, wherein: at least one of the pluralityof retroreflectors is movable relative to the housing, and anarrangement of the plurality of retroreflectors further providesdirectionality information to the UAV.
 13. The location marker asrecited in claim 12, wherein the plurality of retroreflectors isarranged as a grid, the pattern being formed on the grid based onplacement of individual retroreflectors on the grid.
 14. The locationmarker as recited in claim 12, wherein the plurality of retroreflectorsreflect light at less than a 360-degree angle around the locationmarker.
 15. An apparatus, comprising: a housing to form athree-dimensional shape, the housing including a base; and a pluralityof retroreflectors, one or more first retroreflectors of the pluralityof retroreflectors arranged along a first plane that form a firstthree-dimensional pattern and one or more second retroreflectors of theplurality of retroreflectors arranged along a second plane that form asecond three-dimensional pattern, the first three-dimensional patternreadable by an unmanned aerial vehicle (UAV) that is in view of thefirst three-dimensional pattern to communicate specific information tothe UAV to assist the UAV in successfully depositing a package.
 16. Theapparatus as recited in claim 15, wherein the specific informationincludes a presence of one or more obstacles.
 17. The apparatus asrecited in claim 15, wherein the specific information includesinformation associated with at least one of a preferred approach path ora preferred departure path in relation to the housing.
 18. The apparatusas recited in claim 15, wherein the specific information includesinformation on where to deposit the package.
 19. The apparatus asrecited in claim 15, further comprising: a plurality of lights arrangedabout the first plane; and a light controller to control operation ofthe plurality of lights, the light controller selectively causing theplurality of lights to turn on and off to form a time domain signalsequence.
 20. The apparatus as recited in claim 15, further comprising:a display area on the housing to communicate information to at least oneof a UAV or a person.